\[1)\ y = 2^{\frac{x^{2} - 4}{x + 2}};\ \ A(2;\ 1):\]
\[y(2) = 2^{\frac{4 - 4}{2 + 2}} = 2^{0} = 1.\]
\[Ответ:\ \ да.\]
\[2)\ y = tg\left( \frac{x}{3} + \frac{\pi}{4} \right);\ A\left( \frac{3\pi}{4};\ 0 \right):\]
\[y\left( \frac{3\pi}{4} \right) = tg\left( \frac{\pi}{4} + \frac{\pi}{4} \right) = tg\frac{\pi}{2}.\]
\[Ответ:\ \ нет.\]
\[3)\ y = 3^{\frac{x - \sqrt{2}}{x^{2} - 2}};\ \ \ A\left( - \sqrt{2};\ 1 \right):\]
\[y\left( - \sqrt{2} \right) = 3^{\frac{- \sqrt{2} - \sqrt{2}}{2 - 2}} = 3^{- \frac{2\sqrt{2}}{0}}.\]
\[Ответ:\ \ нет.\]
\[4)\ y = ctg\left( \frac{2x}{3} - \frac{\pi}{6} \right);\]
\[A\left( \frac{3\pi}{4};\ \frac{\sqrt{3}}{3} \right):\]
\[y\left( \frac{3\pi}{4} \right) = ctg\left( \frac{\pi}{2} - \frac{\pi}{6} \right) =\]
\[= ctg\frac{\pi}{3} = \frac{\sqrt{3}}{3}.\]
\[Ответ:\ \ да.\]